Surface condenser



R. N. EHRHART.

SURFACE CONDENSEIL,

APPLICATION FILED AUG.2I, \9l8.

1,372, 11 0, Patenmd Mm. 22, 1921.

0 OOOOOOOOOOOOOOOOOO 6 INVENTOR. BY 0 5m ATTORNEYS.

UNITED STATES PATENT OFFICE.

RAYMOND N. EHRHART, OF EDGEWOOD, PENNSYLVANIA, ASSIGNOR TO WESTING- HOUSE ELECTRIC & MANUFACTURING CO., A CORPORATION OF PENNSYLVANIA.

SURFACE CONDENSER.

Specification of Letters Patent.

Patented Mar. 22, 1921.

Toallwhomitnw concern:

Be it known t at I RAYMOND N. Erm- HART, a citizen of the llni'ted States, and a resident of E gewood, in the county of Allegheny and tate of Pennsylvania, have made a new and useful Invention in Surface Condensers, of which the followlng 1s a specification.

This invention relates to surface condensers and has for an object to produce an improved condenser of that type which is well adapted to be constructed in relatively large sizes and which is more efiicient and smaller in pro rtion to its condensing capacity than ot er large size surface condensers now in use and known to me.

Power house conditions are such that it is frequently necessary to limit the exterior dimensions of a surface condenser to conform with the space limitations of the power house. Under ordinary power house conditions a rectangular condenser provides a maximum sectional area and consequently 1s capable of providing a maximum amount of condensing surface in the limited space available for the condenser. Where such condensers are employed in small sizes, for example, condensers having a width or depth of not more than 30 inches, the variation in pressure or as it is termed, the loss in vacuum within the shell, is so small that it is negligible. This, however, is not true of relatively large condensers having shell diameters of 10 or more feet. In such condensers the path along which the steam to be condensed must flow before it is fully condensed is relatively long, and while the condensation may be complete and the vacuum relatively high at some point within the nest of tubes, it will be apparent thatthere will be a loss in vacuum in the vicinity of the steam inlet to the condenser, unless the tube spacin is arranged to facilitate the admission 0 steam to the condensing surface and to insure a quick dissemination of the large volume of steam throughout the nest of tubes. It will be apparent, therefore, that while a rectan lar condenser is capable of accommodating a maximum amount of condensing surface, the surface cannot be efiiciently utilized unless relatively wide tube spacing or a system of steam lanes is employed and these not only increase the cost of the condenser per unit of condensing surface, but also limit the amount of condensing surface which may be effectively employed within a limited space. While a relatively large rectangular condenser of ordinary or usual construction and having a tube spacing comparable to the tube spacing of a small condenser might compare favorably with the small condenser both in condensing capacity per unit of volume and in the proportionate cost of manufacture, the variation in pressure between the point of complete condensation within the nest of tubes and the steam inlet to the condenser would be so great that the beneficial effect of the high vacuum attained by the complete condensation of the steam would be almost entirely lost. This is due to the fact that in such a condenser the paths of steam flow through the nest of tubes would be relatively long and the admission space between the tubes relatively small compared to the volume of steam delivered to the condenser and the amount of surface required to condense it.

A further object of the present invention is therefore to produce a rectangular condenser of relatively large capacity which compares favorably with small condensers both from the standpoint of cost and condensing capacity per unit of condensing surface and in which means are employed for reducing the loss in vacuum or the pressure variations throughout the interior of the condenser shell.

A further object is to produce a rectangular condenser in which the steam admission space to the nest of tubes is materially increased and the length of the paths of steam flow through the nest of tubes is materially decreased, relatively to the area of the admission space, as compared to the usual and ordinary forms of condensers now in use and known to me.

These and other objects which will be made apparent throughout the further de scription of the invention are attained by means of a surface condenser embodying the features herein described and illustrated in the accompanying drawings wherein the figure is a diagrammatic transverse sectional view of a condenser embodying my invention, no consideration being given to details of construction.

As illustrated, the condenser includes a substantially rectangular shell 2 of the usual or ordinary construction and a nest of tubes 3 inclosed within and extending longitudinally of the shell 2. Condensing water is densate discharge port 5, and an air ofitake' port 6. As shown, the inlet port 4 is formed in the top of the shell, the condensate port 5 is formed at the bottom of a hot well 7 and the air ofltake port communicates with the hot well at some point above the normal water level.

The nest of tubes 3 is so disposed within the shell 2 as to provide steam spaces 8 and 9, which communicate with each other and with the inlet port 4 and extend around two sides of the nest of tubes 3. As shown, these steam spaces extend across the top of the nest of tubes and downwardly along one side of the nest between the nest and a side wall 10 of the shell 2. The condensate well 7 and condensate outlet port 5 are located adjacent to the opposite side wall 11 of the shell and the air offtake port preferably communicates with the nest of tubes at a point opposite to the steam space 9 and adjacent to the bottom of the shell.

With the arrangement of tubes above described the free steam space is approximately twice as Wide as the steam space of the ordinary or usual form of rectangular condensers. The portion 9 of the steam space converges from its upper or inlet end downwardly toward the bottom of the condenser. This is accomplished by so arranging the nest of tubes that it gradually increases in width from the inlet face, adjacent the inlet port 4, toward the opposite wall of the condenser shell. As illustrated, the nest of tubes gradually increases in width from the top to the bottom of the condenser. In other words, the cooling tubes increase in number in each linear unit from the top to the bottom of the shell. The converging portion of the steam space 9 provides an adequate delivery space through which steam is admitted into the adjacent admission face of the nest of tubes and atthe same time insures an economical distribution of the condensing surface throughout'the available space, since it is reduced in cross sectional area along its length in substantially direct proportion to the rate of delivery of steam from it to the nest of tubes.

It will be noted that the paths of steam flow through the nest of tubes converge toward the air offtake port 6 and that the air offtake port is so located, with relation to the steam admission space, that all paths of steam flow throughout the nest and to the air offtake port are approximately of equal length.

As "pointed "out in my Patent No. 1,142,784, I have discovered that it is desirable tohave the areas of flow gradually diminish from the inlet of the nest of tubes to the air 0ff take. This diminution of area should be inversely proportional to the "condensation taking place along the paths of flow so that the velocity of the steam is maintained at approximately constant value. Where the areas are so diminished, the condensing sure face is equally effective throughout the entire nest of tubes and variations in pressure within the shell or the loss of vacuum at the inlet of the condenser is reduced to an almost unapprecia-b'le minimum. In other words, a proper distribution of the condenslng surfacealong the paths of steam flow will insure an eflicient operation of the condenser and that the effective vacuum. at the inlet to the condenser is substantially the same as the vacuum maintained at the point of complete condensation of the steam with: in the nest of tubes. By providing the steam spaces '8 and 9 on two sides of the nest of tubes, as illustrated in the drawings and above described, I obtain converging paths of flow and consequently the desirable die minishing areas of flow from the steam space to the air vofttake port. By providing the converging passage 9, I am able to supply steam in adequate amounts to the entire nest of tubes and atthe same time effectively utilize all the space available for ('OIIClGIISlIIg'SUIfflCG. In this connection it will be apparent that the volume of steam entering the end of the passage-9., adjacent to the inlet 4, will gradually decrease as steam enters the nest of tubes and that this decrease in volume is compensated for or taken advantage of by gradually reducing the width of the passage as it approaches the bottom of the condenser shell.

Under some conditions it may. be desirdirection to a point adjacent to the air offtake port 6. With such :an arrangement each steam space feeds into a section of the nest oftubes and consequently the steam flow areas throughout the nest gradually diminish. Where such a bafile is employed it may be desirable to extend it beyond the nest, and in the drawings I have shown a battle 12 which not only divides the steam space of'the condenser, but extends diagonally across the condenser and through, the nest of tubes to a point adjacent the airofftake port. The air offtake port may under such conditionsserve both triangular nests of tubes, and the battle serving as a rain plate protects the lowermost tubes from condensation dropping from the tubes in the upper portion of thecondenser.

While I have-illustrated and described but one embodiment of my invention, it

will be apparent to those skilled in the art that various changes 'modifications, additions and omissions may be made in the apparatus described and illustrated without departing from the spirit and scope of the invention, as'set forth by the appended claims.

What I claim is:

1. In combination in a condenser, a shell having a steam inlet port, a nest of tubes so located within the shell as to provide a free steam space on two sides thereof and in open communication with said inlet port, a baflle extending through and dividing the nest of tubes into two condensin units, the steam flow areas of each of whic diminish from the steam admission portion toward the condensate discharge.

2. In combination in a condenser, a shell having a steam inlet port, and a condensate discharge port located in opposite sides thereof, a nest of tubes so located within the shell as to provide a free steam space on substantially two sides of the nest and in open communication with the steam inlet port, a baflie extending through and dividing said nest into two condenslng units, each of which communicates with substantially a half of said steam ace, and through which the paths of steam ow converge toward the exhaust.

3. In a condenser having a substantially rectan lar shell, a nest of cooling tubes arrange within the condenser shell and spaced from one side thereof so that the top and only one side of the nest of tubes are exposed to condensable fluid entering the condenser, an air ofitake near the bottom of the condenser adjacent the corner remote from the exposed side of the tube nest, and a baflle dividing the nest into two condensing units and extending beyond the nest in :lheddirection of the incoming condensable 4. In a condenser having a substantially rectan lar shell, a nest of cooling tubes arrang within the condenser shell and spaced from one side thereof so that the top and only one side of the nest of tubes are exposed to condensable fluid entering the condenser adjacent the top, a condensate outlet. in the bottom of the condenser adjacent the corner remote from the ex osed side of the tube nest, and a baflle dividing the nest into two condensin units and extending beyond the nest in t he direction of the incoming condensable fluid.

5. In a condenser having a substantially rectangular shell, a nest of cooling tubes arran d within the condenser shell and space from one side thereof so that the top and one side of the nest of tubes are exposed to condensable fluid entering the condenser adjacent the top, a condensate outlet in the bottom of the condenser adjacent the corner remote from the exposed side of the tube nest, and a bafile extending upward diagonally between the tubes from the corner ad'acent the discharge opening so as to divi e the tubes into two oups, each having a diminishin number 0 tubes from the fluid entrance slde of the nest toward the condensate outlet.

6. In a condenser having a substantially rectangular shell, a nest of cooling tubes of decreasing width from the bottom toward the top arranged within the condenser shell and spaced from one side thereof so as to rovide a condensable fluid entrance chamr of diminishing volume from the top toward the bottom of the condenser, an 1nlet for condensable fluid adjacent the top of the shell and communicating with the said chamber, and a condensate outlet adjacent the bottom of the shell.

7. In a condenser having a substantially rectangular shell, a nest of cooling tubes arranged within the shell and spaced from one side thereof so that the top and one side of the nest of tubes is exposed to condensable fluid enterin the condenser, a baflle extending diagona ly between the tubes so as to divide the tubes into separate triangular condensing units adapted to discharge condensate at the lower apex opposite t e exposed entrance side of the tubes, and a condensate outlet adjacent the bottom of the condenser adapted to receive condensate from both the said condenser units.

8. In a condenser having a substantially rectangular shell, a nest of cooling tubes arranged within the shell and spaced from one side thereof so that the top and one side of the nest of tubes is ex osed to condensable fluid enterin the con enser, a baflle extending diagona y between the tubes so as to divide the tubes into separate triangular condensing units adapted to discharge condensate at the lower apex o posite the exposed entrance side of the tubes, a condensate outlet in the bottom of the condenser to which condensate from both said condenser units is delivered, and an outlet for noncondensable fluid communicating with the said condenser units.

9. A condenser having a substantially rectangular shell, a nest of cooling tubes in the shell increasing in number in each linear unit from the top of the condenser substantially to the bottom thereof, a condensate outlet adjacent the bottom of the shell, and means for dividing the tubes into so arate condenser units communicating wit the condensate outlet, whereby the number of tubes in each linear unit increases from such outlet toward the entrance face of the tubes.

10. In combination in a condenser, a shell having a steam inlet port and a condensate discharge port formed therein, a nest of tubes so located Within the shell as to provide a steam space in open communication with the steam inlet and extending across more than one face of the nest of tubes, and an air ofi'take so located with relation to the nest of tubes and the steamspace that the lines of steam flow from the steam space through the nest and toward the air ofitake are of approximatelyequal length.

In testimony whereof, I have hereunto subscribed my name this 17th day of Au- 

